Relating to conventional vehicle drive devices, Japanese Patent Laying-Open No. 2005-333747, for example, discloses an inverter-integrated rotating electric machine directed to facilitate removal of air in a coolant channel (Patent Document 1). According to Patent Document 1, a power control unit (PCU) is mounted on a motor generator serving as a rotating electric machine, with the motor generator and the power control unit integrated with each other.
Japanese Patent Laying-Open No. 2001-119898 discloses a drive device directed to integrate an inverter case into a drive-device case to improve the mountability on a vehicle (Patent Document 2). According to Patent Document 2, the inverter case is provided integrally over the drive-device case. The inverter case stores a heat sink, inverters for a drive motor and a generator motor, a smoothing capacitor, and a control substrate.
Japanese Patent Laying-Open No. 2004-343845 discloses an electric-motor-integrated drive device with a plurality of electric motors integrated into individual case portions, respectively, the drive device being directed to achieve both of integration of the inverters corresponding to the respective electric motors into the drive device and cooling of the inverters (Patent Document 3). According to Patent Document 3, inverter cases are attached to a drive-device case. Japanese Patent Laying-Open No. 2007-99121 discloses a drive device for a hybrid vehicle directed to integrate and downsize inverters (Patent Document 4). According to Patent Document 4, motor generators, a power split mechanism and a power control unit are stored in and integrated with a metal case.
Japanese Patent Laying-Open No. 2003-199363 discloses a control unit for an electric drive device directed to achieve favorable compactness, ease of assembling, productivity, and resistance to vibration (Patent Document 5). According to Patent Document 5, the control unit is attached, in a leaning forward state, to a drive-device case in front of the drive device. Power modules constituting the control unit are arranged in contact with a heat sink implemented by a bottom wall of the case. Capacitors for a smoothing circuit of an inverter are located above the power modules, and a control substrate is located thereabove.
Japanese Patent Laying-Open No. 2002-274201 discloses a power transfer device directed to minimize space for mounting a generator and a motor in a direction perpendicular to a rotation shaft of the generator and an output shaft of the motor (Patent Document 6). In the power transfer device disclosed in Patent Document 6, the rotation shaft of a first motor generator and that of a second motor generator are offset in their radial direction.    Patent Document 1: Japanese Patent Laying-Open No. 2005-333747    Patent Document 2: Japanese Patent Laying-Open No. 2001-119898    Patent Document 3: Japanese Patent Laying-Open No. 2004-343845    Patent Document 4: Japanese Patent Laying-Open No. 2007-99121    Patent Document 5: Japanese Patent Laying-Open No. 2003-199363    Patent Document 6: Japanese Patent Laying-Open No. 2002-274201